Even better – from a certain point-of-view – than a radar trap based on an under-posted speed limit is a radar trap with a changing speed limit. One that can be dumbed-down at random and with no prior notice, at the whim of the same government workers who enforce the limits and profit from that enforcement.

It’s called Variable Speed Limits and the Feds – through the Department of Transportation – are not only encouraging the states to adopt them, they are bribing them to adopt them. Cue Dr. Evil voice – one billion dollars mulcted from taxpayers has been earmarked to mulct taxpayers a second time via “pilot” VSL programs – and at least nine states (New Jersey – naturally – but also Ohio, Wyoming, Oregon, Utah, Florida, Minnesota, Washington and Georgia) are already deploying VSL.

You may have already seen Variable Limits in action. Instead of the usual metal sign with whatever the number chosen at random happened to be at the time the sign was put up silk-screened permanently on it, an electronic sign – with a display that can be changed, literally, at the touch of a button.

At 4:30 p.m., the sign reads – as an example – 75 MPH. But at 4:33 p.m. (and just after you drove past it) the Oz who controls the sign decides the new speed limit shall be 65 MPH. Blink. Just like that, your moment-ago legal rate of travel has become illegal “speeding” – and not only are you subject to a ticket you are more likely to get a ticket because – as far as you know – you aren’t “speeding” and so why worry about that cop up ahead pointing his radar gun at you?

The first is the element of intent, formerly a necessary thing to establish culpability; the idea that a person violated the law on purpose.

But in order for this to be a viable moral concept, the law has to be knowable. A law that is changeable is unknowable. It is – effectively – no law at all. It is the codified whim of whomever has the power to punish people for violating laws that are fundamentally unintelligible.

Kind of like tax law already is. If they want your money, they’ll find some justification to take your money. It’s not about “the law.” It’s about who has power – and is willing to use it.

The second thing has to do with the way speed limits are posted – or rather, are supposed to be posted.

What’s supposed to happen before a speed limit is posted is a traffic study. Monitors set up that observe and record the free-flow speed of traffic on a given stretch of road. The posted limit is supposed to be based on the free-flow speed of 85 percent of the traffic observed – the 85th percentile speed – so that most traffic isn’t “speeding.”

The idea being that most people naturally drive at reasonable speeds and that speed limits should parallel the organic flow of traffic.